要按行为整个表格应用渐变填充列的条件格式，可以使用以下代码示例来解决：

import openpyxl
from openpyxl.utils import get_column_letter
from openpyxl.styles import GradientFill, ColorStop

def apply_gradient_fill(worksheet, start_col, end_col):
    max_row = worksheet.max_row

    # Create the gradient fill
    gradient_fill = GradientFill(stop=("000000", "FFFFFF"))

    # Apply gradient fill to each column
    for col in range(start_col, end_col + 1):
        # Get the column letter
        col_letter = get_column_letter(col)

        # Set the gradient fill to the entire column
        for row in range(1, max_row + 1):
            cell = worksheet[col_letter + str(row)]
            cell.fill = gradient_fill

# Load the workbook
workbook = openpyxl.load_workbook('your_file.xlsx')

# Select the worksheet
worksheet = workbook['Sheet1']

# Apply gradient fill to columns A to C
apply_gradient_fill(worksheet, 1, 3)

# Save the workbook
workbook.save('your_file.xlsx')

请注意，上述代码假设您已经安装了openpyxl库，并且将要操作的Excel文件名为"your_file.xlsx"，并且要应用渐变填充的列范围是从列A到列C。您可以根据实际情况进行修改。